A wide variety of catheters and the like are used for accessing different body lumens in patients, and are used in a large number of different types of procedures. Infusion catheters are well known and widely used for delivering treatment agents into the vascular system or other parts of a patient's body for the treatment of thrombi, tumors, and various other types of undesired tissue or abnormalities. Catheters are also used for introducing contrast agents or dyes, and in the placement of intraluminal treatment devices such as filters and stents. Still other examples of the wide applicability of catheters in medical technology include providing an access pathway for embolization mechanisms, angioplasty devices, and even cutting tools and cameras.
Various entry techniques and pathways may be used to access treatment locations within a body lumen of a patient. Percutaneous access to the cardiovascular system for peripheral intervention techniques is one well known example, and typically involves forming an access opening in a patient's skin, and then guiding a catheter by way of a wire guide through the vasculature while manipulating the wire guide and catheter from a location outside of the patient's body. Once a target location is reached, the catheter may be used in whole or in part to conduct the example procedures mentioned above. Related, but somewhat varying techniques are used to access other body lumens such as the bladder, biliary ducts, etc. A clinician is typically unable to know precisely where a catheter is presently located within a patient without some external mechanism such as an imaging device which enables in vivo visualization on a monitor or the like. Despite a high level of skill among many clinicians, as well as the availability of sophisticated catheter guiding and imaging techniques, properly placing a catheter for delivery of a contrast agent, introduction of a treatment device, or for that matter any other purpose, is still often a tricky endeavor. Even once placed, it is common for catheters or the like to be relatively difficult to maintain in position within the patient.